The arrangement of a stator coil of a general water-cooled generator (a generator adopting a water cooling system) will be explained with reference to FIGS. 5 and 6. FIG. 5 is a longitudinal sectional view showing the arrangement of an end portion of the stator coil. FIG. 6 is a front view showing the end portion of the stator coil when viewed from a clip side.
The stator coil includes a clip 1, a clip cover 2, preplaced brazing filler materials 3, hollow conductors 4, hollow portions 5, a brazing filler materials reservoir 6, a coolant inlet/outlet 7, and solid conductors 8. The preplaced brazing filler materials 3 shown in FIG. 5 are unmelted brazing filler material foils. Note that in the following explanation, the hollow conductors 4 and solid conductors 8 will collectively be referred to as wire conductors in some cases, and hollow conductors 4 will simply be referred to as wires in some cases.
The stator coil of the water-cooled generator is formed by binding a plurality of rectangular hollow conductors 4 and a plurality of rectangular solid conductors 8. Deionized water circulates in the hollow portions 5 of the hollow conductors 4 through the coolant inlet/outlet 7 in order to directly cool the hollow conductors 4 with water. The clip (copper frame) 1 is used to electrically and mechanically connect between the hollow conductors 4 and the solid conductors 8. The clip 1, hollow conductors 4, and solid conductors 8 are joined by brazing. To braze the clip 1, hollow conductors 4, and solid conductors 8, the preplaced brazing filler materials (brazing filler material foils) 3 are placed between the conductors and heated following a predetermined heating procedure while the brazing filler materials are pressed through the clip cover 2 and the temperature is measured with a thermocouple. Consequently, the brazing filler material melts and penetrates between the conductors and between the clip 1 and conductors, thereby combining them. Any excess melted brazing filler materials are collected by the brazing filler materials reservoir 6.
To prevent the molten brazing filler material from entering the hollow portions 5 of the hollow conductors 4 and plugging the holes, the tip of end portions of the preplaced brazing filler materials 3 are slightly retreated inside from the tip of end portions of the hollow conductors 4 and solid conductors 8, as shown in, e.g., FIG. 5. In accordance with this, a sidewall 14 (including a sidewall of the brazing filler materials reservoir 6) inside the clip 1 surrounding the hollow conductors 4 and solid conductors 8 shown in FIG. 5 and FIG. 6 is also retreated inside.
In this arrangement, no brazing filler material enters the hollow portions 5 of the hollow conductors 4, but narrow gaps 13 form in the boundaries between the hollow conductors 4 and/or solid conductors 8, and a coolant enters and stays in these narrow gaps. Consequently, a galvanic corrosion phenomenon occurs in these gaps and dissolves the conductors. This makes the conventional method as described above undesirable.
Under the circumstances, it is desired to provide an armature winding of an electrical rotating apparatus, an electrical rotating apparatus using the same, and a method of manufacturing the same, by which it is possible to prevent a coolant remaining between conductors, and prevent a brazing filler material from entering a hollow portion of a hollow conductor.